1. Technical Field
An aspect of the invention is related to an optical tomographic image photographing apparatus for photographing a tomographic image of an object.
2. Related Art
There is known an optical tomographic image photographing apparatus (Optical Coherence Tomography: OCT) which has an interference optical system and photographs a tomographic image of an object. The optical interference optical system of this apparatus splits a light flux emitted from a light source into a measurement light flux and a reference light flux. This optical interference optical system then guides the measurement light flux to an object, while guiding the reference light flux to a reference optical system. Subsequently, the optical interference optical system combines the measurement light flux, reflected on the object, with the reference light flux, to obtain interference light, and thereafter makes a light receiving device receive this interference light. This apparatus is used for, for example, obtaining a tomographic image of a living body such as an eyeball or skin.
This kind of apparatus also includes an apparatus which displays a tomographic image at a predetermined position on a display monitor by changing an optical path difference between a measurement light and a reference light at any time, even if the object moves while being photographed (refer to JP-A-2008-154939). In such an apparatus, an optical-path-length varying member (for example, a reference mirror) is moved by driving a motor in order to change the optical path difference.